Definition of yield limit
The yield limit is also called the flow limit. When the material is subjected to an external force to a certain limit, it continues to undergo significant plastic deformation even without increasing the load. The yield limit of the material is the stress required to produce a given permanent deformation of the specimen. When the external force of the specimen of the metal material exceeds the elastic limit of the material, although the stress is no longer increased, the specimen still undergoes significant plastic deformation. The phenomenon is called yielding, that is, when the material is subjected to an external force to a certain extent, its deformation is no longer proportional to the external force and produces significant plastic deformation, and the stress at the time of yielding is called the yield limit.